Chemical modification of lignin and lignin derivatives

Abstract

A method for producing an APL is provided in one example embodiment and includes mixing a solvent, a catalyst, a reagent, and a HPL to create a solution, raising the temperature of the solution to a first reaction temperature, raising the temperature of the solution to a second reaction temperature, allowing reactions in the solution to occur for a predetermined amount of time, precipitating the solution to produce a precipitate, and washing, filtering, and drying the precipitate to produce the APL.

What is claimed is: 
     
       1. A method for producing an acetyoxypropyl lignin (APL), comprising:
 mixing a solvent, a catalyst, a reagent, and a hydroxypropylated lignin (HPL) to create a solution; 
 raising a temperature of the solution to a first reaction temperature; 
 raising the temperature of the solution to a second reaction temperature; 
 allowing reactions in the solution to occur for a predetermined amount of time; 
 precipitating the solution to produce a precipitate; and 
 washing, filtering, and drying the precipitate to produce the APL. 
 
     
     
       2. The method of  claim 1 , wherein the HPL contains about three percent moisture. 
     
     
       3. The method of  claim 1 , wherein the solvent is a fifty percent acetic acid solution. 
     
     
       4. The method of  claim 1 , wherein the catalyst is sodium acetate. 
     
     
       5. The method of  claim 1 , wherein the reagent is a fifty percent acetic anhydride solution. 
     
     
       6. The method of  claim 1 , further comprising:
 dissolving the catalyst in the solvent to create a solvent catalyst solution, wherein the catalyst is sodium acetate and the solvent is a fifty percent acetic acid solution; 
 adding the HPL to the solvent catalyst solution; and 
 adding the reagent to the solvent catalyst solution that contains the HPL, wherein the reagent is a fifty percent acetic anhydride solution. 
 
     
     
       7. The method of  claim 6 , wherein the amount of HPL added to the solvent catalyst solution is about thirty percent of a total weight of the solvent catalyst solution. 
     
     
       8. The method of  claim 6 , wherein the solution is precipitated by adding a volume of the solution into a volume of ice water, and wherein the volume of the ice water is five times the volume of the solution. 
     
     
       9. The method of  claim 1 , wherein the precipitate is dried until the precipitate contains about three percent moisture. 
     
     
       10. A trans-esterified lignin/thermoplastic blend comprising:
 a trans-esterified lignin, wherein the trans-esterified lignin is an acetyoxypropyl lignin (APL) created by:
 adding a solvent, a catalyst, and a reagent to a hydroxypropylated lignin (HPL); 
 raising a temperature of the solution to a first reaction temperature; 
 raising the temperature of the solution to a second reaction temperature; 
 allowing the reactions in the solution to occur for a predetermined amount of time; 
 precipitating the solution to produce a precipitate; and 
 washing, filtering, and drying the precipitate to produce the APL; and 
 a thermoplastic. 
 
 
     
     
       11. The trans-esterified lignin/thermoplastic blend of  claim 10 , wherein the solvent is a fifty percent acetic acid solution, the catalyst is sodium acetate, and the reagent is a fifty percent acetic anhydride solution. 
     
     
       12. The trans-esterified lignin/thermoplastic blend of  claim 10 , wherein the catalyst is dissolved in the solvent to create a solvent catalyst solution, wherein the catalyst is sodium acetate and the solvent is a fifty percent acetic acid solution, wherein the HPL is added to the solvent catalyst solution, and wherein the reagent is added to the solvent catalyst solution that contains the HPL, wherein the reagent is a fifty percent acetic anhydride solution. 
     
     
       13. The trans-esterified lignin/thermoplastic blend of  claim 12 , wherein the solution is precipitated by adding a volume of the solution into a volume of ice water, and wherein the volume of the ice water is five times the volume of the solution. 
     
     
       14. The trans-esterified lignin/thermoplastic blend of  claim 12 , wherein the precipitate is dried until the precipitate contains about three percent moisture. 
     
     
       15. A method for producing a biodegradable plastic, the method comprising:
 extruding a trans-esterified lignin/thermoplastic blend, the trans-esterified lignin/thermoplastic blend comprising: 
 a trans-esterified lignin, wherein the trans-esterified lignin is an acetyoxypropyl lignin (APL) created by:
 adding a solvent, a catalyst, and a reagent to a hydroxypropylated lignin (HPL); 
 raising a temperature of the solution to a first reaction temperature; 
 raising the temperature of the solution to a second reaction temperature; 
 allowing the reactions in the solution to occur for a predetermined amount of time; 
 precipitating the solution to produce a precipitate; and 
 washing, filtering, and drying the precipitate to produce the APL; and 
 a thermoplastic. 
 
 
     
     
       16. The method of  claim 15 , wherein an alkyl ester of the HPL exchanges carboxylic acid groups with an alcohol terminated segment of a polyester chain such that long chain polyester segments are covalently-bond to the HPL. 
     
     
       17. The method of  claim 15 , wherein the extent of transesterification of the lignin/thermoplastic blend is controlled such that extensive crosslinking does not occur in order to retain thermoplastic properties. 
     
     
       18. The method of  claim 15 , wherein the biodegradable plastic is a film product, a formed and molded product, an injection molded product, or an extruded product that biodegrades over a period of time into humus through an oxidative process. 
     
     
       19. The method of  claim 18 , wherein polylactide is added to the lignin/thermoplastic blend to extend the period of time that the biodegradable plastic biodegrades. 
     
     
       20. The method of  claim 15 , wherein the trans-esterified APL includes APL and a polyester.